Re: [PATCH] mm: Use WQ_HIGHPRI for mm_percpu_wq.
From: Tejun Heo <tj@kernel.org>
Date: 2017-09-01 13:47:54
Hello, On Fri, Sep 01, 2017 at 07:07:25AM +0900, Tetsuo Handa wrote:
cond_resched() from !PF_WQ_WORKER threads is sufficient for PF_WQ_WORKER threads to run. But cond_resched() is not sufficient for rescuer threads to start processing a pending work. An explicit scheduling (e.g. schedule_timeout_*()) by PF_WQ_WORKER threads is needed for rescuer threads to start processing a pending work.
I'm not even sure this is the case. Unless I'm mistaken, in your workqueue dumps, the available workers couldn't even leave idle which means that they likely didn't get scheduled at all. It looks like genuine multi minute starvation by competing direct reclaims. What's the load number like while these events are in progress? Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>